1. Field of the Invention
This invention relates to optics and, in particular, to holographic recording devices.
The invention can be used in research or industrial applications for studying physical and chemical processes involving variations of refractive indexes, such as dissolution and growth of crystals, electrolysis, and electrophoresis, and for studying hydrodynamic and aerodynamic processes, processes of mass and heat transfer, combustion, biophysical processes of microscopic objects, including biological objects, and also for monitoring the operation of machines and devices, and microelectronic elements.
2. Description of the Prior Art
Holographic devices used for recording holograms and holographic interferograms should be made extremely mechanically stable. Any shift of the interferogram image in the recording plane for a fraction of a period (0.2-0.3 micrometers) during the exposure time practically destroys the recording, and mechanical stability is all important in this case. It can be disturbed by mechanical vibrations, acoustical vibrations, air currents, and thermal expansion of the holographic circuit elements.
The prior art holographic recording devices are bulky and can only be used as stationary laboratory equipment. They are in no way suitable for operation in such extreme conditions as space research facilities or test chambers simulating high altitude conditions.
Known in the art is a holographic recording system (cf., for example, Holography on the NASA Space Shuttle, Palph F. Werker et al, Proceedings of the International Conference "Optical in Four Dimensions", Aug. 4, 1980, Mexico) comprising a package for acoustical and vibration protection, a coherent light source mounted therein, a means for producing a reference beam and a scene beam, which is located downstream the source beam from the coherent light source, and a holographic recorder.
In this holographic recording device the acoustical and vibration protection package comprises a platform and support rails secured thereto by a shock-absorbing system of vacuum holders which are also used to secure the means for producing the reference and scene beams on the platform.
But this device is deficient in that the effect of the low and high frequency oscillations and acoustical vibrations is reduced by making the structure more rigid and the platform heavier, which results in a bulkier device whose dimensions are a limitation in many applications.